When pop singer Katie Melua claimed in her hit song, Nine Million Bicycles, that the universe was 12 billion years old, physicist and well-known author Simon Singh protested.

Scientists had worked out that the universe was 13.7 billion years old, Singh pointed out.

This sparked off a huge fuss, with some sticking up for Singh and others metaphorically putting the boot into him.

Melua was born in Georgia, Russia, and moved with her family to Belfast aged eight, where her father worked as a heart surgeon. Yesterday, the 21-year-old singer “very sportingly” sang a new version of her song on BBC Radio 4, with lyrics rewritten to make it clear the universe was 13.7 billion years old as Singh had stated.

After hearing the new version, Singh was graceful enough to admit: “It was scientifically accurate but musically awful.”

Having made her point, Melua has returned to the original version of the song which has climbed to number five in the British charts.

The controversy began when Singh, author of Big Bang, a history of cosmology, wrote an article with the provocative title, Katie Melua’s bad science.

“In the past, I have found her ballads to be enchanting, but Katie’s latest little ditty is deeply annoying, because she demonstrates a deep ignorance of cosmology,” he said.

He then quoted the offending lyrics:

We are 12 billion light-years from the edge,

That's a guess,

No one can ever say it’s true,

But I know that I will always be with you.

Simon Singh

Singh said: “When Katie sings, ‘We are 12 billion light-years from the edge,’ she is suggesting that this is the distance to the edge of the observable universe, which in turn implies that the universe is only 12 billion years old. This is incredibly frustrating, because there are thousands of astronomers working day and (of course) night to measure the age of the universe, and the latest observations imply a universe that is almost 14 billion years old, not 12 billion.”

Singh, 41, who was born in Britain of parents who came from Punjab, added: “Katie Melua has no right to call the age of the universe ‘a guess’ or quote it as 12 billion years when we now know it to be 13.7 billion years old. You might think that I am being rather uptight, but the role of the scientist is slowly being undermined with a growing belief that scientific results are merely subjective guesses that go in and out of fashion.”

Singh’s big mistake, he now recognises, was to suggest alternative lyrics:

We are 13.7 billion light-years from the edge of the observable universe,

That’s a good estimate with well-defined error bars,

Scientists say it’s true, but acknowledge that it may be refined,

And with the available information, I predict that I will always be with you.

Singh’s outburst brought a rejoinder from the song’s co-writer, Mike Batt, who commented: “Scientists are allowed to split atoms, but please lay off infinitives.”

Yesterday, Singh met Melua and was charmed. “We met in the studio when she re-recorded the track and had a chat. It was quite sweet because Katie had been a member of the astrology club when she was at school. I have learnt my lesson, I’ve heard my lyrics and they weren’t great so I’m going to step back.”

Melua joked: “It was quite hard to get all the syllables in. It was just so funny it really had me giggling for quite a few hours.”

Singh told The Telegraph on Sunday: “Science is science and art is art.”